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1. Field of the Invention
The invention relates to communication networks, and specifically, to a method and system for providing continuity testing in communication networks.
2. Description of the Prior Art
The development of advanced communication networks has taken on critical importance with the dramatic rise in consumer demand for higher quality services. Continuity testing in communication networks is one method of ensuring the quality of services. A continuity test ensures bearer channel connectivity prior to call completion. The continuity test is generally performed on a pre-determined percentage of calls to verify bearer channel connectivity between a pair of switches.
FIG. 1 illustrates an example of a continuity test in a public switched telephone network (PSTN) using signaling system 7 (SS7). On FIG. 1 the calling party removes the receiver from the calling party""s telephone 100. The originating switch 101 detects the off-hook and provides a dial tone to telephone 100. Responsive to receiving the dial tone, the user enters the digits for a call destination. The originating switch 101 processes the entered digits and provides an initial address message (IAM) to the network 102. The IAM message includes a continuity test flag that indicates to the network 102 that a continuity test will be performed on the bearer channel between the network 102 and the originating switch 101. The originating switch 101 then sends a test tone over the bearer channel to the network 102. Responsive to sending the test tone, the originating switch 101 starts a timer. The network 102 loops the test tone back to the originating switch 101. If the test tone is received back in the originating switch 101 before the timer times-out, the continuity test is successful and the originating switch 101 sends a continuity message to the network 102. The continuity message confirms the continuity test is complete and successful. If the test tone is not received back in the originating switch 101 before the timer times-out, the continuity test is failed and the call is cleared. Responsive to a successful continuity test, the network 102 provides an IAM message to the terminating switch 103 and reserves a call connection between the originating switch 101 and the terminating switch 103. The terminating switch 103 sends an address complete message (ACM) to the network 102 and the call is completed between telephones 100 and 104 in the conventional fashion.
Unfortunately, packet-networks do not effectively support continuity testing. These networks typically require installation of communication hubs in the customer premises. The communication hubs are controlled by an out-of-band call agent that does not have knowledge of bearer path connectivity when call setup messages are received from the communication hubs.
The present invention advances the art by providing a communication hub that performs continuity testing in communication networks. Advantageously, the present communication hub controls and performs continuity testing in packet networks and other networks connected to the packet network. Also advantageously, service assurance is provided before call completion and early detection of network failures is realized.
In one embodiment of the invention, the communication hub comprises a processor coupled to an interface. The processor is configured to process a continuity test instruction to generate a request for continuity acknowledgment message. The interface is configured to receive the continuity test instruction and transmit the request for continuity acknowledgment message. If a continuity acknowledgment message is received in the communication hub responsive to the request for continuity acknowledgment message, the continuity test is passed. If the continuity acknowledgment message is not received in response to the request for continuity acknowledgment message, the continuity test is failed.
In another embodiment of the present invention the communication hub is comprised of an interface coupled to a processor and a tone generator. The processor is configured to process a continuity test instruction to generate a request for continuity acknowledgment message. In some examples of the invention, the processor is also configured to process a continuity test tone instruction to direct the tone generator to provide continuity test tones to another communication network. The tone generator is configured to generate the continuity test tones under control of the processor. The interface is configured to receive the continuity test instruction and the continuity test tone instruction and transmit the request for continuity acknowledgment message and the continuity test tones for the processor.
In the context of the present invention the first, second, third, fourth, etc. connotations used to reference the messages, the calls, and the devices are used for the purpose of differentiating between different messages, different calls, and different devices and are not used to indicate a message sequence, call sequence or processing sequence. Also in the context of the present invention, an on-network call session is defined as a call session between two devices connected to the same communication network. An off-network to on-network call session and an on-network to off-network call session are defined as an incoming call session or an outgoing call session, respectively, between two devices connected to different communication networks. For example, an incoming call session or an outgoing call session between a call device connected to a packet network and a call device connected to the PSTN. In-band is defined as using the bearer portion of a communication path, for example, over the bearer channel in an asynchronous transfer mode (ATM) connection. Those skilled in the art will appreciate that in some environments, such as an Internet Protocol (IP) environment, in-band could simply be a pair of addresses, such as the address of the originating device and the address of the terminating device.